Assessing the taxonomy and status of the Bluestone sculpin (Cottus sp.1)
Dates
Start Date
2021-10-01
End Date
2023-09-30
Summary
The Bluestone sculpin (Cottus sp.1) is an undescribed freshwater fish endemic to the New River system in Virginia and West Virginia. The taxonomic status of the Bluestone sculpin is unresolved, and its range often overlaps with congeners, with which it may hybridize. The species is most often found in small, cool streams with gravel and rubble dominated substrates. Juveniles and adults are found most often in runs and riffles of boulder and rubble (Jenkins and Burkhead 1994). Many of the streams presumed to be within the species’ range run along highways and may be vulnerable to non-point source pollution. Treatment plants and agricultural runoff are also potential threats to the species. To address the science needs of the Bluestone [...]
Summary
The Bluestone sculpin (Cottus sp.1) is an undescribed freshwater fish endemic to the New River system in Virginia and West Virginia. The taxonomic status of the Bluestone sculpin is unresolved, and its range often overlaps with congeners, with which it may hybridize. The species is most often found in small, cool streams with gravel and rubble dominated substrates. Juveniles and adults are found most often in runs and riffles of boulder and rubble (Jenkins and Burkhead 1994). Many of the streams presumed to be within the species’ range run along highways and may be vulnerable to non-point source pollution. Treatment plants and agricultural runoff are also potential threats to the species.
To address the science needs of the Bluestone sculpin, genetics analyses are needed to fully describe the species, assess hybridization, and understand connectivity between populations. Surveys to determine the species range are also needed and should be targeted at historic sites, cave openings, and springs within the New River drainage. Other predictors of Bluestone sculpin presence may be in habitat sites similar to the where Clinch, Holston, and Kanawha sculpin are known to occur within their respective rivers.
The only formal description of the Bluestone sculpin is by Jenkins and Burkhead (1994) and is based on morphology. The Bluestone sculpin is one of several members of the banded sculpin (Cottus carolinae) complex, and part of a subset of this complex is referred to as the Appalachian Highlands group. The Appalachian Highlands group consists of the following: Bluestone sculpin, Albino cave sculpin, Kanawha sculpin, Pigeon River Race, Sequatchie River Race, Clinch, and Holston sculpins). Almost no genetic data exist at NCBI for the Bluestone sculpin, with the exception of two mitochondrial DNA sequences from the same single voucher specimen in Kinziger et al (2005; 2007). Other Appalachian Highland sculpins are similarly depauperate of genetic information. Phylogenetic analyses based on a mtDNA fragment in Kinziger et al. (2007) placed the Bluestone sculpin in a well-supported clade with samples of the Midlands Race from the Tennessee River, and the Kanawha sculpin. The Clinch and Holston sculpins were placed in different clades from the Bluestone sculpin. While this analysis was informative, sample sizes of each taxon were low, which may not provide an accurate reflection of haplotype diversity. In addition, inclusion of more mtDNA loci, as well as nuclear loci would give a more comprehensive representation of the relationships among these taxa including fine-scale structure and hybridization.
Objectives:
The overarching objective is to employ genomic techniques to more accurately describe the taxonomy of Bluestone sculpin, its treatment as a species, and to assess the extent of hybridization with other Appalachian Highland sculpins. Specific objectives to facilitate the overarching objective include:
Objective 1: Coordinate with Virginia and West Virginia fish and wildlife agencies, as well as academic institutions and museum collections nationwide to obtain contemporary and historical tissue samples of Bluestone and other Appalachian Highland sculpins for genomic analyses.
Objective 2: Utilize long range PCR to amplify the mitogenome of Bluestone and other available sculpins in 2-4 fragments to create libraries for targeted high throughput sequencing and mitogenome recovery. Alignment of these mitogenomes and subsequent phylogenomic analyses will provide insight into the relationships among the sequenced sculpins from the perspective of the fast evolving and non-recombinant mitochondrial genome.
Objective 3: In addition to mitogenomic analyses, hundreds of nuclear genes targeted through use of a validated bait capture panel of ultraconserved elements (UCEs) among Percomorph fishes (including Scorpaeniformes) will be sequenced. Phylogenomic analyses of these sequences will be compared with the mitogenomes to understand the evolutionary history among the sculpins examined. We will attempt to delimit species using by applying the multi-species coalescent model in the BPP software (Yang 2015).
Objective 4: Report and interpret the findings of this study to US Fish and Wildlife Service and appropriate state wildlife agencies.
